Electric toothbrushes customarily have a bristle support that can be driven in a rotatorily oscillating manner and supports a bristle field comprising a plurality of bristle tufts, the bristle field in the overall having an approximately round, in particular circular, contour, with an oval or elliptical base area also being possible. The working surface of the bristle field in this arrangement is formed by the free ends of the bristle tufts, which can have various cross-sections. For example, in addition to the customary round bristle tufts having a circular cross-sectional area, a bristle field can also have elongated bristle tufts having an elongated, slender cross-sectional contour, or angular bristle tufts having an angular cross-sectional contour.
In order to achieve improved cleaning performance and a more pleasant brushing sensation, it has more recently been proposed to no longer design the working surface of the bristle field defined by the free ends of the bristle tufts to be flat, but to instead give the working surface a three-dimensional topography, in which some of the bristle tufts are higher than others and some of the bristle tufts have at the free ends thereof a tuft end face that is inclined toward the longitudinal axis of the bristle tuft.
In order to provide a bristle field with such three-dimensional working surfaces, the bristle tufts are trimmed accordingly, that is to say, cut at the ends thereof, so as to achieve the desired topography. Depending on the contouring of the working surface and on the cut required for this at the tuft end, this may be more or less difficult. On the one hand, the bristles tend to give way during the cutting operation, since they themselves are elastic. On the other hand, problems arise in case of dense bristle arrangements in that different bristle tufts cannot always easily be cut separately from one another, as a result of which it is not possible to achieve stepped contours.
Apart from this, in the case of angularly cut tuft ends it is often also problematic to round the bristle ends themselves in the desired manner, because the angular cut results in a bristle end that is too pointed per se, which is difficult to round or would lose too much length during the rounding process.
From DE 38 28 571 A1 a method is known for producing brushware, wherein bristle tufts are fixed to a bristle support by melting the bristles, which are made of a thermoplastic material, at the ends thereof that have been inserted into holes in the bristle support. For this purpose, the hole or hole wall of the bristle support is heated to a temperature above the melting temperature of the bristles.
From DE 195 19 291 A1 and EP 11 38 222 B1 additional methods for producing a brush head are known, in which the bristles are not fused to the bristle support, but instead are secured by means of a so-called anchor-tufting method. This is done by inserting bristle tufts, which have been folded into a U-shape, into a tuft socket in the bristle support using a metal plate that is placed between the limbs of the U-shaped bristle tuft, wherein the laterally projecting anchor plate digs itself into walls in the bristle support.
This, however, does not solve the aforementioned problems related to cutting the tuft ends.
The present invention addresses these problems by providing a method wherein it is possible to perform a cut, even of more complicated, more difficult tuft end contours, using conventional, simple cutting tools, while giving the individual bristles an easy-to-round cut contour.
This and other features, aspects, advantages, and variations of the present invention will become evident to those skilled in the art from a reading of the present disclosure with the appended claims and are covered within the scope of the claims.